Coaster brake for vehicles



Oct. 15, 1929. E. SACHS v 1',731, 7zs

chasm: BRAKE m vmucnzs Filed Sept. 6, -1

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I 1nvent0r Dr Ernst Sachs uittor'n ys Patented Oct. 1 5, 1929 4 UNITED STATES PATENT OFFICE ERNST sncns, or scnnoss MAINBERG,'NEAR scnrwnmrnnr, navnnm, GERMANY coasrnn. BRAKE ronvnnrcnns Y Application filed September a, 1927, Serial No.

Theinventionrelates to the expansible brake sleeves in internal brakes for wheel hubs, es

pecially in back-pedalling coaster-brakes for' inder and its mantle, so that proper operation of the'brake will not be prevented by a dis arrangement or relative displacement of the main parts thereof.

This object is attained in a very simple and effective manner by interconnecting the elements of the brake through an annular split ring engaging in a circumferential groove in the peri hery of the brake cylinder and in a similar acing groove provided on the inside I of the mantle, while a slit of the mantle in substantially longitudinal direction allowing expansion thereof is disposed so as to cross or traverse the longitudinal or axial slits of the brake cylinder, any'obstacle to the rotation of the mantle upon the cylinder being thus prevented, notwithstanding the fact that elements are locked against relatlve axial displacement :b the same means.

An embodiment 0 the invention is illustrated in the accompanying drawmg which forms a part of this specification and 1n which-'- b Figure 1 is an end view of the brake mem- Figure 2 a side elevation thereof, partly in section; and

Figures 3 and 4 represent corresponding views of a modified embodiment of the mvention.

Like-numerals denote like parts throughout all figures of the drawing.

Referring to Figs. 1 and 2, the illustrativesleeve-shaped expansible brake member is composed of a main bod or cylinder 5 made preferabl of steel an a brake-mantle or shell 6 of raking material, such as soft metal 217,848, and in Germany September 14, 1926.

or alloy, such for example as brass, which -encloses the main body and is preferabl, of the same axial length as said body. In t c construction shown, the main body 5 comprises two "cylinder segments having opposite inwardly directed lugs 7 serving for non-rotatably securing the said body.

The brakemantle orshell6 consists of a onepiece sleeve formed with a longitudinally disposed slit 8 and bearing upon the segments of the main body with resilient pressure, said slit being extended in a helical line across or over a part of the periphery of the brake mantle (Fig. 2). The elfect of this arrangement is that during the braking operation, the brake member will be pressed uniformly against the inner surface of the hub owing to the fact thattheslit in the brake mantle does not at any time coincide with the axial slits 11 of the main body 5, but instead crosses the latter slits. The result of this construction is that a uniform expansion of the brake mantle is produced at all points while the mantle is ree to turn upon the main body. Furthermore the brake mantle will also contract easily over the slits 11 of the mainbody. The same result may be obtained with a construction such as shown in Fi' s. 3 and 4, wherein the slit 9 in the'mantle 6 1s V-shaped or formed by angularly dis osed slitortions extending in opposite irections rom apoint midway of the brake in helical or spiral lines of large pitch.

In order to effectively revent axial move ment of the brake man e relatively to the main body, anannularcspring 10 is rovided between said body and mantle, sai spring being received and held within opposing As the brake mantle is capable of turning conjunction with the annular spring. From this construction soft braking and easyexpansion and contraction of the brake results.

Expanding or spreading of the described brake member may be efi'ected in different ways, as for example, by means of conical brake applying members engaging the interiorly-beveled ends of the main body, as more fully described in my prior Patents Nos. 777,811, dated December 20, 1904, and 960,710, dated June 7, 1910. 1

It will be perceived from the. foregoing description that the invention is capable of various embodiments. What I, therefore, claim as my invention is- 1. In an internal hub brake, the combination with an expansible c lindrical main body of an elastic brake mant e rotatably mounted on said body, said body and mantle being formed with opposed circumferential grooves in their contacting surfaces, and an annular spring received'in said grooves so as in effect to be embedded partly in the main body and partly in the brake-mantle, substantially as described.

2. In an internal hub brake, the combination of a cylindric main body composed of segments, a slitted brake mantle rotatably mounted on said body, and an annular spring fixed between said mantle and body and adapted to interconnect the same against relative axial movement.

3. In an internal hub brake, the combination of a main body composed of segments, an annular spring received partly in a circumferential groove formed in said body, and a split brake mantle rotatably mounted on the main body and formed 'with a circumferential groove opposing the groove in said body for receiving the remaining 0 art of said spring.

4. In an internal hub rake, the combination of a main body composed of segments, a brake mantle rotatably mounted on said body and having a substantially helical slit longitudinally thereof, and an annular spring engaging in opposed circumferential grooves formed in the contacting surfaces ofsaid main body and mantle.

5. In an internal hub brake, the combination of a main body comprising segmental 

